1. Field of the Invention
The present disclosure relates generally to a novel pressure switch and its method of operation in an electrical circuit for indicating whether the pressure of a fluid is either above or below a preselected value.
2. The Prior Art
Numerous types of sensors, switches and gauges have been developed and used in the prior art for indicating the pressure of a fluid. For a specific example, two totally different types of switches have been used in the automotive industry to visually display oil pressure in an automobile instrument panel.
One of those types of switches typically includes a variable resistor designed to provide a variable readout by way of a gauge. Due in part to the expense of this first type of switch, the industry has turned predominantly to a second type of switch, the so-called "idiot light" that is illuminated when the oil pressure falls below a predetermined critical value. The prior art switch for this arrangement is somewhat simple in design, but is not without inherent disadvantages.
More specifically, the prior art switches for the idiot light arrangement are designed for an on-off operation and include one fixed and one movable contact element, the movable contact element having somewhat of a flattened T-shaped cross section. This particular cross sectional configuration is disadvantageous for several reasons. For example, this element is more costly than the corresponding component proposed by the present invention. Further, the configuration of this element requires an unnecessary enlargement of the additional ancillary components of the pressure switch, thereby unnecessarily increasing the cost of the prior art devices.